Improvement in air pumps and engines



T. BEACH. A ir Pumps and Engines. N0. 137,123, PatntedMarch 25,1873L UNITED STATES PATENT OFFICE..

THOMAS BEACH, OF FREEPORT, PENNSYLVANIA, ASSIGNOR OF ONE-HALF HIS RIGHT TO JOHN C. MCOLELLAND, OF SAME PLAGE.

IMPROVEMENT 1N AIR PUMPS AND ENemEs.

Specification forming part of Letters Patent No. 137,123, dated March 25, 1873.

\ To all whom it may concern:

Be it known that I, THOMAS BEACH, of Freeport, in the county of Armstrong and State of Pennsylvania, have invented a new and useful Improvement in Air Pump and Engine; and I do hereby declare the following to be a full, clear, and exact description thereof'.

The efficiency of compressed air as a motive power depends largely on the density to which it is compressed 5 and after a certain moderate degree of den sity has been attained it is difficult, if not practicallyimpossible, by the use of the ordinary air-pump, to force more air iuto the compressed-air reservoir.

I have devised an improved air-compressing apparatus in which a stratum or layer of water or other like liquid is interposed between the discharge valve or port of a revolving series of air-pumps and the air-receiving space of the reservoir or receiver, whereby I am enabled to continue the work of compressing the air to any desired degree of density, limited only by the power employed in compressing and the strength of the materials used. I also connect the exhaust-pipe of the air-engine, by which the power of the compressed air is utilized, with the air-receiving ports or valves of the compressing-pump,

To enable others skilled in the art to make and use my improvement, I will proceed to describe its construction and mode of operation, reference being had to the accompanying drawing, in which- Figure l is a vertical sectional view of my apparatus. Fig. 2 is a ground or plan view through the line x x, Fig. l. Fig. 3 is a sectional plan view ofthe devices above the line x1 x1, inverted. Figa is a view, enlarged in perspective, of a portion of my apparatus; and Fig. 5 is a sectional view through the line a2 x2, Fig. 1.

Like letters of reference indicate like parts in each.

The frame-work A is of any suitable construction, and on it is mounted an air-tight reservoir or receiver, A', made of boiler-plate iron or other suitable material, and of any desired size. In the bottom of this receiver is a circular aperture, in which I arrange a circular revolving plate, B. Over it, so as t0 constitute practically the bottom of that part of the receiver A1, is a xed plate, A2. To the revolving shaft B1 the revolving plate B is fixed. This shaft plays in suitable steps, B2, so as always to be properly centered. To the under side of the revolving plate B, and in circular order, is fastened a series of air-pumps, O, two or more, each one having at its upper end an air-port, C1, through which air is forced into the receiver A1. Each piston C2, by its stem G3, swivel C, and a toothed rack, O5, receives a pumping motion alternately up and down from a pinion D. Each pinion D is arranged on a shaft, D', which in turn is ar` ranged on and in the radial line of a drivingwheel, E. This wheel has gear-teeth on its under side, as at E', by which it is set in motion. On each shaft D' is also arranged a gearwheel, F, as in Figs. l and 2, or a double segmental gear-wheel, F', as in Fig. 4. As the driving-wheel E goes around, the wheels F or F' engage alternately the curved toothed racks G G', one, G, being so arranged that, at the proper time in the revolution of the cylinders, and through such part of the revolution as may be necessary, it will impart an upward motion to the pistons O2, acting, of course, through the shaft D', pinion D, toothed rack C5, &c. The corresponding toothed rack G' has directly the reverse arrangement-that is, it is at the opposite side of the machine, and in proper position to impart by the means already indicated, and at the proper time, a downward stroke to the pistons (l2 for taking in a fresh supply of air. In the bottom plate A2, and at the proper points for the egress of air from and ingress of air into the air-pump O, I make the ports H H', preferably oblong, and curved to the path of the cylinder-ports C1, so as to allow time for the outflow and inflow of air at each opposite stroke of the pistons C2, it being kept in mind that the revolving motion in the machine described is continuous, though it may be intermittent, if so preferred. The port H opens directly into the receiver A1, but over the other port H' is an inverted air-chamber, A3, from which a fresh supply of uncompressed air is supplied to the air-pumps() at the down-stroke of each piston. The work of taking air from the chamber A3 and compressing it into the receiver A1 thus goes on continuously, and if the air-pumps C are arranged in close proximity, as they may be, one pump will be all the while taking air and another compressing so long as the machine is in operation. i

To insure, now, that the work of compress ing air into the receiver A1 shall go on even to the extent of taking from the pumps into the receiver air less dense, and consequently less compressed, than the air already in the receiver, I introduce into the receiver A1 a stratum of water, two or three inches in depth, more or less. It will now be seen that no matter what may be the relative densities of the bodies of air in the receiver and in the pumps, as soon as the ports G1 and I-I make an open passage-way from one to the other, the air of the pump U, as its piston C2 goes up, will rise through the water into'tlie airspace above. The piston C2 is, of course, at this point at or near the upper end of its stroke. The only effect on it of the pressure of air in the receiver on the water will be to force a portion of the water through the ports H and G1 into the pump-cylinder; but in such case the pump changes from a pneumatic to a hydraulic pump, and, acting on the principles Well known in the hydraulic press, forces the water upward again through the ports G1 and II, and compresses the air thus forced or allowed to escape into the receiver, along with that previously pumped in by the same operation. rlhis operation may be continued till the air is compressed to any desired density, limited only by the power applied to the pumps and the strength of the materials used in the construction' of the apparatus. Instead of water other suitable liquid may be employed. Also the apparatus for imparting a reciprocating motion to the pump-pistons may be varied by employing other equivalent means, and any desired form or construction of air-pump may be used in connection with a layer, stratum, or column of water, which, when each piston completes its stroke, shall occupy the space immediately above the piston. And the same result may be secured by introducing a thin stratum of water inside each pump-cylinder above its piston, and in this latter case the ports by which the air passes into the receiver should be provided each with a check-valve of suitable form.

In Fig. 1 I have also shown an air-engine, in which J represents the main cylinder; J f, the air-chest 5 K, the pipe by which compressed air is supplied from the receiver A1 to the engine, and K/ the pipe by which the exhaust air is conveyed, either uncompressed or at a less density, to the air-chamber A3, from which thc air-pumps C take their fresh supplies ot' air. The construction of these devices will be readily understood by the skilled mechanic.

In starting the air-compressing apparatus, y

or when it is desired to use the compressed air under circumstances such that it cannot profitably be reused,- eommunication may be opened from the external air to the air-receiving ports in any of the ways known to the art, and such communication may be intermittent, as with an ordinary check-valve, or it may be always free, as in the common air-pump, according to the different circumstances under which this apparatus is to be used.

I do not claim, broadly, the use of water as a valve-packing, since I am aware that such use of water is old.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. A series of air-pumps revolving around a common axis, and successively brought under an air-discharge port or ports at the upward stroke of the piston in each, substantially as set forth.

2. A revolving plate arranged between the discharging ends of a series of air-pumps and an air-receiver, in combination with a stratum of water or other suitable liquid, as a check valve to the pumps, substantially as set forth. In testimony whereof I, the said THoMAs BEACH, have hereunto set my hand.

THOMAS BEACH. Witnesses:

W. N. PAXTON, J AMES I. KAY. 

